1. Field
The present disclosure relates to a catalyst for CO2 reforming of hydrocarbons, a method of manufacturing the same, and a hydrocarbon reforming process using the same.
2. Description of the Related Art
Hydrocarbons, such as natural gas and petroleum gas, may be reformed in the presence of a reforming material (e.g., carbon dioxide, water vapor, and oxygen) and a catalyst. For example, methane in natural gas may produce gases such as hydrogen and carbon monoxide via a carbon dioxide reforming (CDR) reaction represented by the following Reaction Schemes.CH4+CO2→2CO+2H2 [ΔHo=247.3 kJ/mol]  (1)CO2+H2→CO+2H2O [ΔHo=41 kJ/mol]  (2)
Such reactions are endothermic and require a relatively high temperature such as at least 650° C. for a forward reaction to proceed. One of the major problems occurring in such reactions is catalyst degradation via catalyst coking, for example represented by the following reaction schemes.CH4C+2H2[ΔHo=122.3 kJ/mol]  (3)2COC+CO2[ΔHo=125.2 kJ/mol]  (4)
Reaction (3) represents CH4 cracking, which is a primary cause for deactivation. Reaction (4), also known as a Boudouard reaction, does not really occur at a high temperature. Such reactions cause the generation of carbon, which is then deposited onto the catalyst, leading to a decrease in a reaction surface area, clogging of the pores in the catalyst, and acceleration of the support degradation. As a result, the catalyst eventually loses its activity. A sintering phenomenon is also one of major concerns that may cause a decrease in the number of active sites of the catalyst when it undergoes a relatively high temperature reaction. Due to the sintering phenomenon, a thermally unstable catalyst tends to aggregate to grow into a relatively large particle when it is subjected to a relatively high temperature reaction. The sintering phenomenon may result in a decrease in the number or the size of support pores, and a decrease in the interface area of a catalyst/support. Accordingly, the sintering may lead to a smaller area of the catalytically active surface and make it more difficult for the reaction gas to diffuse into the catalytically active site. Moreover, the sintering may cause a decreased interface between the catalyst and the support and thus may weaken the bonding strength therebetween. As a result, the conversion rate of the reaction gas becomes lower, the internal pressure of a reactor increases, and the durability of the catalyst/support is deteriorated.